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1947-48 Theatre Catalog, 6th Edition, Page 341 (327)

1947-48 Theatre Catalog, 6th Edition
1947-48 Theatre Catalog
1947-48 Theatre Catalog, 6th Edition, Page 341
Page 341

1947-48 Theatre Catalog, 6th Edition, Page 341

Film Magazines

The magazines are made of sheet metal spinnings, mounted on cast aluminum support frames in which is mounted the fire trap roller assembly. This assembly is comprised of two fioating, hardened and ground rollers, gravity held against a single accurately positioned main trap roller. Clearances between rollers and film is held to less than 0.005

> inch, guaranteeing effective fire trap action.

Feed reel holdback tension is adjustable by means of a knurled tension nut compressing the holdback spring against a washer type brake clutch assembly.

Takeup power is transmitted through a chain drive from the projector mechanism to the constant torque clutch assembly, mounted on the takeup spindle shaft. Takeup film tension is of a designed value and is not field variable.

Torque uniformity is such as to accommodate any reel size up to 2,000 feet capacity.

Film magazines and fire traps have been approved by the Underwriters Laboratories and the various state approval agencies.


Projector lubrication is by both oiling and greasing. A single point visible oiling system serving the oiling requirements and Alemite nttings are used for the greasing points. The system is of a gravity feed visible reservoir type and feeds all bearing assemblies requiring the lighter type of lubrication,

Silicone grease is used in the shutter assembly and this is supplied every 500 hours by means of an Alemite gun.

FIGURE 6-Proiection lens focusing is accomplished by a micrometer screw located outside the proiector case with the lens focus lock located inside the proiector case, for permanent, accurate projector lens focusing. The focusing mount lens holder barrel extends through the projector case.


Pad Roller Assembly

The sprocket pad roller assembly (Figure 7) is mounted integrally with the sprocket shaft housing assemblies and its operation is that of a lever arm, its final position determined by a spring motivated plunger pressing into adjustable registry points located on the sprocket shaft housing assembly. The pad rollers themselves are removable for cleaning or replacement from the operating side of the projector by the removal of the pad roller operating knob which releases the front pad roller bearing plate. The pad rollers are made of hardened and ground steel and are set so as to allow ample clearance with the sprocket teeth.

The operating means for the pad roller is of adequate size to insure long life and ease of operation.

Proiector Switching

All projector switching is accomplished in a terminal box located at the top of the mechanism case (Figure 8) and these facilities consist of a motor switch, framing light switch, and changeover button. This location places all changeover operations within the span of a hand. This eliminates the spread-out switching method so commonly used, with its attendant operating difiiculties. This method of switching was incorporated at the request of many operators who felt that something could be done about eliminating the two hands and one foot requirements of projector changeover operation.

H. I. Head Cooling

An adjunctive ventilation unit is sup plied for high intensity are operation, acting to both cool the film rails and film to such a degree as to render the use of a heat filter unnecessary and in that manner guarantee maximum light on the screen. The temperature of the rails under 80-ampere, high-intensity projection conditions is reduced to less than 120 degrees at the end of a 20minute period of operation. Ventilation is accomplished in a pressure blast and exhaust manner by both a blast of air directed across the aperture, film rails and film in such a manner as to not cause film disturbance during projection and still carry the heat away from the film, aperture and rails to a loctaion where the head heat exhaust fan is effective. This additionally removes heat radiated from not only the aperture rails and baffles, but from the shutter as well. Film cooling is quite effective by this means an a substantial increase in film life is obtained, as compared with conventional methods of film projection.

The head ventilation is supplied as an adjunctive unit, complete in itself, and readily attachable to all 12000 projector heads.

Scanning Mechanics

The sound head portion (Figure 9) of the projector is built around an internally stabilized fiywheel filter system utilizing a coupling fiuid relatively uniform in its performance over wide variations of temperature. This rotary stabilizer functions in conjunction with the film loops as established for its correct operation so effectively as to reduce speed variations or flutter to less than 0.25 percent of the mean operating speed.

FIGURE 7eThe sprocket pad roller assembly is mounted integrally with the sprocket shaft housing assemblies and its operation is that of a lever arm, its final position determined by a spring-motivated plunger pressing into the registry points located on the sprocket shaft housing assembly.
1947-48 Theatre Catalog, 6th Edition, Page 341